Field
The present disclosure relates generally to communication systems, and more particularly, to a method and apparatus for energy efficient signaling and operation in densely deployed networks.
Background
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example of an emerging telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). It is designed to better support mobile broadband Internet access by improving spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards using OFDMA on the downlink (DL), SC-FDMA on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE technology. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
Dense network deployment can significantly improve wireless system capacity. In such dense network deployment, Low Power Nodes (LPN) provide service to other User Equipment (UE) in their vicinity. An LPN may comprise a UE relay, a Remote Radio Head (RRH), a pico cell, femto cell, etc. A pico cell has a power of approximately 30 dBm, and a UE relay has a power of approximately 23 dBm. Thus, a “low” power node has a power that is less than approximately 46 dB, which is the typical transmit power of a Macro cell. A UE relay is a UE that has both a backhaul link, e.g., to an eNB or other LPN, as well as an access link for another UE. Dense deployments may include a large number of LPNs.
Although the use of LPNs can greatly increase the capacity of the wireless system, such operations also place a strain on the battery of the LPN. Thus, there exists a need to ensure energy efficient operation of LPNs involved in such dense network deployment.